Apparatus for electrolytically penetrating shell casings



Apnl 10, 1956 c. F. BOWERSETT 2,741,594

APPARATUS FOR ELECTROLYTICALLY PENETRATING SHELL CASINGS Filed April 5,1950 IN VEN TOR. CHARLES E BOWERSE TT United States APPARATUS FORELECTROLYTICALLY PENETRATING SHELL CASINGS Charles F. Bowersett, Laurel,Md. Application April 5, 1950, Serial No. 154,122

3 Claims. (Cl. 204-212) (Granted under Title 35, U. S. Code (1952), see.266) This invention relates generally to metal cutting apparatus andmore particularly to the new and improved electrolytically penetratingthe hardened casings of explosive filled shells, or the like, for thepurpose of removing therefrom their explosive filling without detonatingor firing the explosive filling.

The operation of dismantling recovered enemy projectiles for the purposeof analyzation and study has always been a precarious and highlydangerous procedure and particularly so since the development of fuzingmechanisms adapted to explode the shell if an attempt is made to removethe fuze therefrom.

It has been found, however, that much of the danger involved indismantling projectiles of the explosive type may be obviated if priorto an attempt to extract the fuze therefrom,'the explosive filling ofthe shell is first removed. The removal of the explosive from a shellhas been done heretofore by first producing an opening in the shellcasing adjacent the explosive filling and through which steam or boilingwater is then admitted under pressure to wash from the shell the nowmolten exploslve.

The procedure of penetrating a projectile, for the purpose indicated,has been done most frequently heretofore by either of two methods: bydrilling, when penetrating projectiles of the soft or mild steelvariety, or by grinding when opening projectiles of the hardened armorpiercing type. By either of the methods indicated considerable heat isgenerated along the cutting edge of the tool and, even though liquidcoolants may be directed continuously against the surface being cut,explosions have frequently occurred as the result of either heat orsparks being produced as the tool bites through the last remainingportion of the shell and penetrates the explosive filling thereof.

A further disadvantage of conventional methods of cutting hardenedprojectile shells is the ditficulty in producing therein an opening ofsufficient size that, after the remoyal of the explosive therefrom,access is had to the booster charge of the fuze which should likewise beremoved prior to any attempt to extract the fuze and thus forego thepossibility of ignition of the booster which could very effectively sodamage the control mechanisms of the fuze as to render it of little orno value as a source of military information.

The apparatus provided by the present invention for cutting explosivefilled shells, or the like, includes an arrangement for rotating theprojectile to be cut about its longitudinal axis and concurrentlytherewith directing thereagainst from a plane perpendicular to this axisa plurality of high velocity jets of negatively charged electrolyticfluid thereby to cause an electrolytic erosion of the surface of theshell along a line drawn through the points of contact therewith of thejets and thus to sever the shell as the erosion thereof penetrates tothe explosive filling without detonation of the same.

It is an object of the present invention to provide an cally cutting anexplosive filled projectile, or the like, by

applying a stream of negatively charged electro-conductive fluid to acircumferential portion thereof.

A still further object is to provide a metal cutting apparatus wherein apositive voltage is applied to the part being cut and a negativelycharged electrolyte is directed at high velocity thereagainst.

A still further object is to sever an explosive filled shell by applyinga negatively charged electrolyte thereagainst at high velocity while theshell is continuously rotating.

Other objects and many attendant advantages of this invention will bereadily appreciated as the same becomes better understood by referenceto the following detailed description when considered in connection withthe accompanying drawing wherein the single figure thereof is a planview in section of the cutting apparatus of the present inventionaccording to a preferred embodiment thereof.

Referring now to the drawing, there is shown thereon a device suitablefor use with the present invention, the device including an open endtank, generally designated 5, adapted to receive and retain a copiousquantity of liquid 14 such, for example, as brine or a solution of acidor the like and having the required electrolytic char-' acteristics forthe purpose intended.

Centrally arranged within the tank and extending upwardly from thethickened base portion 6 thereof to which it is secured as by brazing,welding or the like, is a vertically disposed hollow member 7 wherein ispress fitted, cemented or the like, a tubular sleeve 8 composed ofsuitable insulating material, such, for example, as fiber impregnatedplastic. Formed about the upper or free end of the hollow member 7 andpreferably made integral therewith is an annular flange 9 whereon isformed an inverted conical baffle 10 the purpose of which will becomeclearly apparent as the description proceeds.

Closely fitted within the sleeve 8 and adapted for jour nalling thereinis a shaft section 11 to which is secured for rotation thereby amounting plate or platform 12, about a vertical axis and above the levelof the fluid in the tank,.the platform being adapted to support forrotation the article to be cut, for example, the explosive filled shellor projectile 13. An insulating washer 15 interposed between themounting plate 12 and flange 9 is so arranged as to receive therein theend of the sleeve 8 which is effective to cooperate therewith toinsulate the shaft and mounting plate 12 from the hollow member 7 andtank 5 and electrolyte contained therein. Arranged about the tank is anannular conduit or header 16 from which project inwardly into the tank aplurality of pipe sections 17 equipped with jet nozzles 18; header 16,pipe sections 17 and nozzles 18 being generally disposed in a planenormal to the axis of rotation of platform 12. Fluid from the header 16is directed by the nozzles 18 forcibly against the side of theprojectile as the projectile rotates. Fluid to the header is suppliedthrough a pipe conduit 19 leading from a high pressure pump 20preferably of the gear type and connected with the tank by way ofconduit 21 of which the end 22 thereof extends upwardly into the tankand is preferably provided with a suitable strainer 23, the pump andconduits constituting a hydraulic conduit system for supplying thefluid.

The operation of the device will now be described. The projectile 13 orsimilar such article to be cut is first mounted upon the plate orplatform 12 in a position sub- Patented Apr. 10, 1956 tantiallycentrally thereof so that the axis of the proectile'is substantiallycoincident with the axis of rotation )f the platform, whereby theposition of the projectile vill tremain substantially equidistant fromthe nozzles 18 pleted from the positively energized projectile-tothenega :ively charged nozzles 18 by way of the fluid streams or lets 30thereby to effect an electrolytic action .or galvanic erosion of theshell surface along the line 31 correspondinglto the point ofintersection of the charged electrolyte. emitted .athi'gh'velocity fromeach 'of the nozzles. The back gear assembly generally designated 32 andpreferably formed as an integral part of the motor generator unit 26 isshown as connected with the shaft section 11 as by the belt and pulleyarrangement 33 and 34 respectively, that during the interval of thecutting operation of the device, the object being cut is rotated betweenthe, concentrated jets 30 whereby an annular groove 31 is .cut in thismanner through the metallic casing of the shell to the explosive fillingthereof whereupon the casing isseparated and the explosive therein maythereafter be removed safely. V

The cutting efiect of the apparatus is greatly facilitated 4 3 h wereof. h a en e practiced otherwise than as specifically described.

The invention described hereinmay be manufactured and used by or for theGovernment of the United States of America for governmental purposesWithout payment of any royalty thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent ofthe United Statesisa 1. Apparatus of the character disclosed for cuttingan explosive filled metallic shell comprising, in combination, a tankcontaining a quantity of electrolytic fluid, a platformmountedfor'rotation in saidtank about an-axis and above the level of thefluid, said platform being adapted by the arrangementand force of theliquid streams or'jets against the surface being cut by applying theretoa scrubbing action to removeas it is formed the oxide resulting from thegalvanic erosion of the metallic casing of the .shell. 7 V v Thearrangementof the end of the baffie 10in close but spaced adjacency witha depending flange portion 36 of .the mounting plate 12 preventsspattering of the electrolyte. from the tank to the'surface of theinsulating Washer 15 which would consequently reduce its dielectriccharacteristics.

T he spattering 37 of the electrolyte from the shell due to the velocitywith which it strikes the surface thereof after being directedthereagainst by the nozzles 18, so breaks up the liquid particles as toprevent an effective electrical circuit being established between theshell and tarikas the electrolyte returns to the latter afterperformingfitscuttingoperation upon the shell. Ina similar manner theliquid falling to the surface of the plate 12 is thrown. therefrom in adiscontinuous stream or spray:38 as the plate is rotated during thecutting operation of the device.

Wherein as in the illustrated embodiment of the invention, theelectrolyte emitting nozzles are shown in; a

single .plane it will be understood that this has been done for thepurpose of description only and that the nozzles may be arranged, ifdesired, in different planes Without departing from the spirit and scopeofthe invention.

The present invention may further be advantageously employed for cuttinga hole or a plurality of holes in metallic plates or the like, ,itbeing-only necessary to stop rotation of the platform 12 as by removalof the belt 33 effective to connect the driving'pulley of the shaft 11with the backgear assembly 32' forming a part of the m otor g eneratorunit 26. 1

Obviously many other modifications and variations of the presentinvention are possible in the light of the above teachings. It istherefore to be understood that within to support said shell with theaxis of the'shell substantiallycoincident with said axis of rotation ofthe-platform, a plurality of jet nozzles arranged around said shell anddisposed in a planenormal to 'said axis of rotation and directed towardthe shell, a hydraulic system including a pump for conducting 'fluidfrom said tank and forcing the .same through said nozzles as highvelocity jets which impinge upon said shelhmea'ns electricallyinsulating said platform-from, said tank, and electrical means for applying'concurrently a positive voltage to said platform and a negativevoltage to said tank whereby the-shell is positively charged and thejets of fluid forced from the nozzles are negatively charged andelectrolytic action occurs v along a line where the plane of the jetnozzles intersects the surface. of the shell as the shell is rotated 'tocut through the same without firing said explosive.

2. Apparatus as defined in claim 1 in which ofrolationof the platform isvertically disposed.

.3. Apparatus ofthe characterdisclosed forcutting an explosive filledmetallic shell comprising, in combination,

a tank containing a quantity of electrolytic fluid, .said tank having ahorizontally disposed bottom, a vertical hollow membercentrally arrangedin'said tank and passing upwardlythiou gh saidbottomto. a point abovethe level of the fluid, a tubular sleeve composed of insulating Imaterial 'andfittedwithin said member, a rotatable shaft journalled insaid sleeve and extending upwardly beyond said rne mbe na horizontalplatform secured to the upper end of-saidv "shaft, a washer ofinsulating material be tween said member and said platform, saidplatform being adaptedv to support said shell for rotation with the axisof, the .shellsubstantially coincident with the axis of said shaft,means for rotating said shaft, a plurality of jet nozzles mounted onsaid tank and arranged around said shell, said nozzles beingdirectedtoward said shell and disposed'in .a plane perpendicular to the axisthereof, a conduitv system connected to said nozzles and the bottom ofsaid tank, said system including a pump for drawing fluid from the tankand forcing the same through; the noz 'zles. as high velocityjets whichimpinge upon the shell,

and an. electrical circuit. connected to said shaft and said;

tank and having means for applying a positive voltage to the shellthrough the shaft and platform as -the shell rotates andfor applying anegative voltage to the fluid through said tank whereby the shell issevered by electrolytic action without firing said explosive.

References Cited in the file ofithis patent UNITED STATESPATENT-S EngleSept. 18,

sh ms t qnma b r the axis

1. APPARATUS OF THE CHARACTER DISCLOSED FOR CUTTING AN EXPLOSIVE FILLEDMETALLIC SHELL COMPRISING, IN COMBINATION, A TANK CONTAINING A QUANTITYOF ELECTROLYTIC FLUID, A PLATFORM MOUNTED FOR ROTATION IN SAID TANKABOUT AN AXIS AND ABOVE THE LEVEL OF THE FLUID, SAID PLATFORM BEINGADAPTED TO SUPPORT SAID SHELL WITH THE AXIS OF THE SHELL SUBSTANTIALLYCOINCIDENT WITH SAID AXIS OF ROTATION OF THE PLATFORM, A PLURALITY OFJET NOZZLES ARRANGED AROUND SAID SHELL AND DISPOSED IN A PLANE NORMAL TOSAID AXIS OF ROTATION AND DIRECTED TOWARD THE SHELL, A HYDRAULIC SYSTEMINCLUDING A PUMP FOR CONDUCTING FLUID FROM SAID TANK AND FORCING THESAME THROUGH SAID NOZZLES AS HIGH VELOCITY JETS WHICH IMPINGE UPON SAIDSHELL, MEANS ELECTRICALLY INSULATING SAID PLATFORM FROM SAID TANK, ANDELECTRICAL MEANS FOR APPLYING CONCURRENTLY A POSITIVE VOLTAGE TO SAIDPLATFORM AND A NEGATIVE VOLTAGE TO SAID TANK, WHEREBY THE SHELL ISPOSITIVELY CHARGED AND THE JETS OF FLUID FORCED FROM THE NOZZLES ARENEGATIVELY CHARGED AND ELECTROLYTE ACTION OCCURS ALONG A LINE WHERE THEPLANE OF THE JET NOZZLES INTERSECTS THE SURFACE OF THE SHELL AS THESHELL IS ROTATED TO CUT THROUGH THE SAME WITHOUT FIRING SAID EXPLOSIVE.